The federal judges who appointed Kenneth W. Starr have decided to intercede in an escalating dispute between the independent counsel and Attorney General Janet Reno over her intent to investigate Starr's handling of the Monica S. Lewinsky matter.

In a one-sentence order made public yesterday, the judges agreed to decide whether Reno's probe should be halted, setting the stage for a court battle that will bring to public light a legal feud thus far conducted in secret and that could produce new revelations about the origins of the investigation that led to President Clinton's impeachment.

The three federal appellate judges charged with overseeing the independent counsel process acted in response to court papers filed Feb. 16 by the Landmark Legal Foundation, a conservative advocacy organization based in Herndon. The group claimed that the Justice Department lacks the authority to investigate an independent counsel and asked that the judges order Reno to halt her inquiry because of its potential to interfere with Starr's work.

Since the earliest days of the Lewinsky investigation, congressional Democrats and attorneys for Clinton have repeatedly complained that Starr abused the powers of his office. Responding to those concerns, Reno advised Starr in mid-January that the Justice Department intended to investigate a variety of allegations, including claims that Starr's assistants attempted to coerce Lewinsky into cooperating with their investigation and that Starr's office collaborated with lawyers helping to bring the Paula Jones sexual harassment lawsuit against Clinton.

Both Reno and Starr have 15 days to present written responses to the three-judge panel's request, which was filed last Friday but released only yesterday.

The court action comes amid private negotiations between Starr and Reno over the best course of action for a probe of the independent counsel's alleged abuses. Reno has insisted, according to government officials, that the federal law governing special prosecutors gives her the power to investigate such allegations because it authorizes an attorney general to remove an independent counsel for good cause. Starr, meanwhile, has asserted that any Justice Department investigation would violate his autonomy, the officials said.

In recent days aides to Starr and Reno have been discussing a possible compromise, officials said. An outside investigator would be named in deference to Starr's wishes that the investigation not be handled within the Justice Department, but Reno would retain the final say as to whether any offenses, if proven, are serious enough to merit Starr's removal or other sanctions.

The independent counsel process was created in the aftermath of Watergate to avoid the conflicts of interest that would result if attorneys general investigated allegations against the presidents who appointed them. The law allows an attorney general to remove an independent counsel for "good cause" but does not define what type of misconduct would meet that standard or how to investigate any improprieties. Neither the Justice Department nor Starr's office would comment publicly on the negotiations. Reno is so determined to formulate the inquiry and conduct it in secret that she has authorized an unusually aggressive internal inquiry to find and punish the sources of news stories about her handling of the allegations against Starr, department officials said.

Deciding what standard should be applied to judge these allegations has become a complex legal puzzle that must be resolved with no precedents to go on.

If proven true, none of the allegations on its own appears serious enough to justify firing Starr, particularly because he did not directly participate in some of the most controversial episodes, among them the initial "sting" of Lewinsky on Jan. 16, 1998, at the Ritz-Carlton Hotel at Pentagon City.

One of the issues under debate within the Justice Department and at Starr's office is whether a series of lesser offenses can add up to a pattern of misconduct that is cause for removal.

In the past the Justice Department has held that an independent counsel can be investigated only for allegations of offenses that would justify removal because that sanction is the only one allowed in the law. "An independent counsel bears a special relationship to the Department of Justice," the department said in a 1997 letter to a defense attorney in explaining its decision not to investigate allegations that it acknowledged would have prompted an ethics inquiry against an ordinary federal prosecutor.

Starr is now pressing the Justice Department to define the standards it is applying to this probe before proceeding further, officials said.